Rotary printing machines utilizing rubber blankets usually have blankets in which reinforcement strips extend over the width of the blanket--see, for example, U.S. Pat. No. 2,850,970, BRODIE, and corresponding German published patent application No. 1,124,051. The slot formed in the cylinder, extending essentially axially thereof, then must be wide enough to permit insertion of the reinforcement strip behind the portion of or end of the rubber blanket which had previously been inserted. Thus, the slot must have a width at the outer circumference of the blanket cylinder which corresponds to the thickness of the rubber blanket plus the thickness of the reinforcement strip. When the rubber blanket is stretched on the cylinder, a gap will remain since the blanket is thinner than the reinforcement strip. In operation, as the slot of one cylinder meets the slot of a counter cylinder, for example on perfecting printing if both rubber cylinders carry printed subject matter, the engagement force of the cylinders against each other drops abruptly as the gaps meet each other and then again rises abruptly. The run-over of the cylinder slots, thus, cause problems which cannot be entirely eliminated by the addition of bearer rings at one, or both ends of the blanket cylinder. It is unavoidable that oscillations within the cylinder will result. This is particularly noticable when both cylinders have cylinder slots although, if only one cylinder has a cylinder slot, for example for prime printing only, the drop-off of engagement force of the rubber blanket cylinder with the counter or impression cylinder is also noticable.